Remove an is_a check
Don't pass nil to fails_with?
Rename compiler attribute to name
Move compiler failure matching logic into failure object
Use a separate class for GNU compiler failures

major_version is now only used internally by the failure object
Eliminate consideration of major_version

The major version is implicit in the compiler name. Since the name is
used when matching failures to compilers, we don't need to consider the
major version separately.
libvirt 1.2.7
libvirt: update 1.2.7 bottle.

Closes #31319.

Signed-off-by: Misty De Meo <mistydemeo@gmail.com>
Remove dead code
Eliminate a nil check
youtube-dl 2014.08.02.1
youtube-dl: update 2014.08.02.1 bottle.

Closes #31315.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
Add another TODO
Add inspect to CompilerFailure
Add inspect to CxxStdlib
Add predicate methods to Tab to match BuildOptions